In a magnetic disk storage unit with a self contained source of organic lubricant within the head disk enclosure wherein a recirculating air flow is present. the lubricant molecules bidirectionally transfer between the air stream and the source and between the air stream and the surfaces of the disk media. It is necessary to control the vapor pressure of the lubricant source to provide vapor phase transport of the lubricant molecules between the source and the disk surfaces to maintain a mono-molecular lubricant on the disk surfaces that is within the range of 3 to 15 Angstroms in accordance with the principle of Langmuir Kinetics. The rigid disks have on the recording surfaces a carbon overcoat which has an affinity for airborne organic molecules. Such a system is shown and described in U.S. Pat. No. 4,789,913.
The above vapor transport lubrication system requires that the lubricant supply be kept cooler than each of the disks in the drive during operation.